financially supported by the National High Technology Research and Development Program of China(No.2016YFB0402201)
A large-mode-area(LMA) ytterbium-doped photonic crystal fiber(PCF) with core NA of 0.034 and core diameter of 50 μm was made by the stack-and-draw technique. The core is formed by Yb3+/Al3+/F-/P5+ co-doped silica...